CCL20-CCR6 Cytokine Network Facilitate Treg Activity in Advanced Grades and Metastatic Variants of Hepatocellular Carcinoma

The Therapeutic Potential of Physical Exercise in Cancer: The Role of Chemokines

The global increase in cancer cases and mortality has been associated with inflammatory processes, in which chemokines play crucial roles. These molecules, a subfamily of cytokines, are essential for the migration, adhesion, interaction, and positioning of immune cells throughout the body. Chemokines primarily originate in response to pathogenic stimuli and inflammatory cytokines. They are expressed by lymphocytes in the bloodstream and are divided into four classes (CC, CXC, XC, and CX3C), playing multifaceted roles in the tumor environment (TME). In the TME, chemokines regulate immune behavior by recruiting cells such as tumor-associated macrophages (TAMs) and myeloid-derived suppressor cells (MDSCs), which promote tumor survival. Additionally, they directly influence tumor behavior, promoting pathological angiogenesis, invasion, and metastasis. On the other hand, chemokines can also induce antitumor responses by mobilizing CD8+ T cells and natural killer (NK) cells to the tumor, reducing pro-inflammatory chemokines and enhancing essential antitumor responses. Given the complex interaction between chemokines, the immune system, angiogenic factors, and metastasis, it becomes evident how important it is to target these pathways in therapeutic interventions to counteract cancer progression. In this context, physical exercise emerges as a promising strategy due to its role modulating the expression of anti-inflammatory chemokines and enhancing the antitumor response. Aerobic and resistance exercises have been associated with a beneficial inflammatory profile in cancer, increased infiltration of CD8+ T cells in the TME, and improvement of intratumoral vasculature. This creates an environment less favorable to tumor growth and supports the circulation of antitumor immune cells and chemokines. Therefore, understanding the impact of exercise on the expression of chemokines can provide valuable insights for therapeutic interventions in cancer treatment and prevention.

Complex Role of Regulatory T Cells (Tregs) in the Tumor Microenvironment: Their Molecular Mechanisms and Bidirectional Effects on Cancer Progression

Regulatory T cells (Tregs) possess unique immunosuppressive activity among CD4-positive T cells. Tregs are ubiquitously present in mammals and function to calm excessive immune responses, thereby suppressing allergies or autoimmune diseases. On the other hand, due to their immunosuppressive function, Tregs are thought to promote cancer progression. The tumor microenvironment (TME) is a multicellular system composed of many cell types, including tumor cells, infiltrating immune cells, and cancer-associated fibroblasts (CAFs). Within this environment, Tregs are recruited by chemokines and metabolic factors and impede effective anti-tumor responses. However, in some cases, their presence can also improve patient's survival rates. Their functional consequences may vary across tumor types, locations, and stages. An in-depth understanding of the precise roles and mechanisms of actions of Treg is crucial for developing effective treatments, emphasizing the need for further investigation and validation. This review aims to provide a comprehensive overview of the complex and multifaceted roles of Tregs within the TME, elucidating cellular communications, signaling pathways, and their impacts on tumor progression and highlighting their potential anti-tumor mechanisms through interactions with functional molecules.

miR-22 promotes immunosuppression via activating JAK/STAT3 signaling in cutaneous squamous cell carcinoma

Immunotherapy is the only approved systemic therapy for advanced cutaneous squamous cell carcinoma (cSCC), however, roughly 50% of patients do not respond to the therapy and resistance often occurs over time to those who initially respond. Immunosuppression could have a critical role in developing treatment resistance, thus, understanding the mechanisms of how immunosuppression is developed and regulated may be the key to improving clinical diagnosis and treatment strategies for cSCC. Here, through using a series of immunocompetent genetically engineered mouse models, we demonstrate that miR-22 promotes cSCC development by establishing regulatory T cells (Tregs)-mediated immunosuppressive tumor microenvironment (TME) in a tumor cell autonomous manner. Mechanism investigation revealed that miR-22 elicits the constitutive activation of JAK/STAT3 signaling by directly targeting its suppressor SOCS3, which augments cancer cell-derived chemokine secretion and Tregs recruitment. Epithelial-specific and global knockouts of miR-22 repress papilloma and cSCC development and progression, manifested with reduced Tregs infiltration and elevated CD8+ T cell activation. Transcriptomic analysis and functional rescue study confirmed CCL17, CCL20 and CCL22 as the main affected chemokines that mediate the chemotaxis between miR-22 highly expressing keratinocyte tumor cells and Tregs. Conversely, overexpression of SOCS3 reversed miR-22-induced Tregs recruitment toward tumor cells. Clinically, gradually increasing Tregs infiltration during cSCC progression was negatively correlated with SOCS3 abundance, supported by previously documented elevated miR-22 levels. Thus, our study uncovers a novel miR-22-SOCS3-JAK/STAT3-chemokines regulatory mechanism in defining the immunosuppressive TME and highlights the promising clinical application value of miR-22 as a common targeting molecule against JAK/STAT3 signaling and immune escape in cSCC.

An emerging research: the role of hepatocellular carcinoma-derived exosomal circRNAs in the immune microenvironment

Hepatocellular carcinoma (HCC), the most common primary malignancy of the liver, is one of the leading causes of cancer-related death and is associated with a poor prognosis. The tumor microenvironment (TME) of HCC comprises immune, immunosuppressive, and interstitial cells with hypoxic, angiogenic, metabolic reprogramming, inflammatory, and immunosuppressive features. Exosomes are nanoscale extracellular vesicles that secrete biologically active signaling molecules such as deoxyribonucleic acid (DNA), messenger ribonucleic acid (mRNA), microribonucleic acid (miRNA), proteins, and lipids. These signaling molecules act as messengers in the tumor microenvironment, especially the tumor immunosuppressive microenvironment. Exosomal circRNAs reshape the tumor microenvironment by prompting hypoxic stress response, stimulating angiogenesis, contributing to metabolic reprogramming, facilitating inflammatory changes in the HCC cells and inducing tumor immunosuppression. The exosomes secreted by HCC cells carry circRNA into immune cells, which intervene in the activation of immune cells and promote the overexpression of immune checkpoints to regulate immune response, leading tumor cells to acquire immunosuppressive properties. Furthermore, immunosuppression is the final result of a combination of TME-related factors, including hypoxia, angiogenesis, metabolic reprogramming, and inflammation changes. In conclusion, exosomal circRNA accelerates the tumor progression by adjusting the phenotype of the tumor microenvironment and ultimately forming an immunosuppressive microenvironment. HCC-derived exosomal circRNA can affect HCC cell proliferation, invasion, metastasis, and induction of chemoresistance. Therefore, this review aimed to summarize the composition and function of these exosomes, the role that HCC-derived exosomal circRNAs play in microenvironment formation, and the interactions between exosomes and immune cells. This review outlines the role of exosomal circRNAs in the malignant phenotype of HCC and provides a preliminary exploration of the clinical utility of exosomal circRNAs.

The role of myeloid-derived suppressor cells in liver cancer

MDSCs are immature myeloid immune cells, which accumulate in models of liver cancer to reduce effector immune cell activity, contribute to immune escape and treatment resistance. The accumulation of MDSCs suppresses the role of CTL and the killing effects of NK cells, induces the accumulation of Treg cells, and blocks the antigen presentation of DCs, thus promoting the progression of liver cancer. Recently, immunotherapy has emerged a valuable approach following chemoradiotherapy in the therapy of advanced liver cancer. A considerable increasing of researches had proved that targeting MDSCs has become one of the therapeutic targets to enhance tumor immunity. In preclinical study models, targeting MDSCs have shown encouraging results in both alone and in combination administration. In this paper, we elaborated immune microenvironment of the liver, function and regulatory mechanisms of MDSCs, and therapeutic approaches to target MDSCs. We also expect these strategies to supply new views for future immunotherapy for the treatment of liver cancer.

Hypoxia-driven immunosuppression by Treg and type-2 conventional dendritic cells in HCC

BACKGROUND AND AIMS

Hypoxia is one of the central players in shaping the immune context of the tumor microenvironment (TME). However, the complex interplay between immune cell infiltrates within the hypoxic TME of HCC remains to be elucidated.

APPROACH AND RESULTS

We analyzed the immune landscapes of hypoxia-low and hypoxia-high tumor regions using cytometry by time of light, immunohistochemistry, and transcriptomic analyses. The mechanisms of immunosuppression in immune subsets of interest were further explored using in vitro hypoxia assays. Regulatory T cells (Tregs) and a number of immunosuppressive myeloid subsets, including M2 macrophages and human leukocyte antigen-DR isotype (HLA-DR^lo ) type 2 conventional dendritic cell (cDC2), were found to be significantly enriched in hypoxia-high tumor regions. On the other hand, the abundance of active granzyme B^hi PD-1^lo CD8⁺ T cells in hypoxia-low tumor regions implied a relatively active immune landscape compared with hypoxia-high regions. The up-regulation of cancer-associated genes in the tumor tissues and immunosuppressive genes in the tumor-infiltrating leukocytes supported a highly pro-tumorigenic network in hypoxic HCC. Chemokine genes such as CCL20 (C-C motif chemokine ligand 20) and CXCL5 (C-X-C motif chemokine ligand 5) were associated with recruitment of both Tregs and HLA-DR^lo cDC2 to hypoxia-high microenvironments. The interaction between Tregs and cDC2 under a hypoxic TME resulted in a loss of antigen-presenting HLA-DR on cDC2.

CONCLUSIONS

We uncovered the unique immunosuppressive landscapes and identified key immune subsets enriched in hypoxic HCC. In particular, we identified a potential Treg-mediated immunosuppression through interaction with a cDC2 subset in HCC that could be exploited for immunotherapies.

ELF3-AS1 contributes to gastric cancer progression by binding to hnRNPK and induces thrombocytosis in peripheral blood

Numerous studies have reported that a variety of long noncoding RNAs (lncRNAs) can promote the proliferation, invasion, and migration of different tumor cells. However, different lncRNAs regulate cell functions in various forms, and the exact mechanisms are not clear. Here, we investigated the effect of the lncRNA ELF3-AS1 on gastric cancer (GC) cell function and explored the exact mechanism. Quantitative real-time polymerase chain reaction was used to detect the expression of ELF3-AS1 in GC tissues and adjacent nontumor tissues. Knockdown and overexpression of ELF3-AS1 was used to detect the effect of ELF3-AS1 on cell function. Potential downstream target genes were identified using RNA transcriptome sequencing, while RNA immunoprecipitation, chromatin immunoprecipitation, and Western blotting were performed to explore the tumor promotion mechanisms of ELF3-AS1. We observed that ELF3-AS1 was highly expressed in GC tissues, and high ELF3-AS1 expression predicted poor prognosis. The knockdown of ELF3-AS1 significantly inhibited cell proliferation, migration, and epithelial-mesenchymal transition and promoted apoptosis. Mechanistic investigations revealed that ELF3-AS1 may regulate the downstream target gene, C-C motif chemokine 20, by binding with the RNA-binding protein hnRNPK. Additionally, we found that high ELF3-AS1 expression was associated with thrombocytosis. Interleukin-6 and thrombopoietin may be involved in ELF3-AS1-induced paraneoplastic thrombocytosis. Together, our results demonstrate that aberrantly expressed ELF3-AS1 in GC may play important roles in oncogenesis and progression and is expected to become a new target for the diagnosis and treatment of GC.

DUSP12 regulates the tumorigenesis and prognosis of hepatocellular carcinoma

Background

Dual specificity protein phosphatase (DUSP)12 is an atypical member of the protein tyrosine phosphatase family, which are overexpressed in multiple types of malignant tumors. This protein family protect cells from apoptosis and promotes the proliferation and motility of cells. However, the pathological role of DUSP12 in hepatocellular carcinoma (HCC) is incompletely understood.

Methods

We analyzed mRNA expression of DUSP12 between HCC and normal liver tissues using multiple online databases, and explored the status of DUSP12 mutants using the cBioPortal database. The correlation between DUSP12 expression and tumor-infiltrating immune cells was demonstrated using the Tumor Immune Estimation Resource database and the Tumor and Immune System Interaction Database. Loss of function assay was utilized to evaluate the role of DUSP12 in HCC progression.

Results

DUSP12 had higher expression along with mRNA amplification in HCC tissues compared with those in normal liver tissues, which suggested that higher DUSP12 expression predicted shorter overall survival. Analyses of functional enrichment of differentially expressed genes suggested that DUSP12 regulated HCC tumorigenesis, and that knockdown of DUSP12 expression by short hairpin (sh)RNA decreased the proliferation and migration of HCC cells. Besides, DUSP12 expression was positively associated with the infiltration of cluster of differentiation (CD)4+ T cells (especially CD4+ regulatory T cells), macrophages, neutrophils and dendritic cells. DUSP12 expression was positively associated with immune-checkpoint moieties, and was downregulated in a C3 immune-subgroup of HCC (which had the longest survival).

Conclusion

These data suggest that DUSP12 may have a critical role in the tumorigenesis, infiltration of immune cells, and prognosis of HCC.

Clinical Significance of Fusobacterium nucleatum Infection and Regulatory T Cell Enrichment in Esophageal Squamous Cell Carcinoma

A variety of pathogenic microorganisms promote tumor occurrence and development through long-term colonization in the body. Fusobacterium nucleatum (F. nucleatum) is abundant in precancerous esophageal lesions and is closely related to the malignant progression of esophageal squamous cell carcinoma (ESCC). The invasion of exogenous microorganisms can reshape the immune microenvironment, make the immune system incapacitated, and assist tumor cells in immune escape. A variety of pathogenic microorganisms induce the recruitment of regulatory T cell (Tregs) to allow tumor cells to escape immune surveillance and provide favorable conditions for their own long-term colonization. Tregs are one of the major obstacles to tumor immunotherapy and have a significant positive correlation with the occurrence and development of many kinds of tumors. Because F. nucleatum can instantly enter cells and colonize for a long time, we speculated that F. nucleatum infection could facilitate the immune escape of tumor cells through enrichment of Tregs and promote the malignant progression of ESCC. In this study, we found a significant concordance between F. nucleatum infection and Tregs infiltration. Therefore, we propose the view that chronic infection of F. nucleatum may provide favorable conditions for long-term colonization of itself by recruiting Tregs and suppressing the immune response. At the same time, the massive enrichment of Treg may also weaken the immune response and assist in the long-term colonization of F. nucleatum. We analyzed the correlation between F. nucleatum infection with the clinicopathological characteristics and survival prognosis of the patients. F. nucleatum infection was found to be closely related to sex, smoking, drinking, degree of differentiation, depth of invasion, lymph node metastasis, and clinical stage. The degree of differentiation, depth of infiltration, lymph node metastasis, clinical stage, and F. nucleatum infection are independent risk factors affecting ESCC prognosis. Additionally, the survival rate and median survival time were significantly shortened in the F. nucleatum infection positive group. Therefore, we propose that long-term smoking and alcohol consumption cause poor oral and esophageal environments, thereby significantly increasing the risk of F. nucleatum infection. In turn, F. nucleatum infection and colonization may weaken the antitumor immune response through Treg enrichment and further assist in self-colonization, promoting the malignant progression of ESCC.

Chemokines in hepatocellular carcinoma: a meta-analysis

Accumulating evidence suggests that chemokines may play an important role in the formation and mediating of the immune microenvironment of hepatocellular carcinoma (HCC). The purpose of this meta-analysis was to explore the differences in blood or tissues chemokines concentrations between HCC patients and controls. Online databases, namely PubMed, Web of Science, Embase and Cochrane Library, were systematically searched for relevant articles published on or before 15 January 2020. Standardized mean differences (SMDs) with corresponding 95% confidence intervals of the chemokines concentrations were calculated as group differences between the HCC patients and the controls. Sixty-five studies met the inclusion criteria for the meta-analysis. Altogether they consisted of 26 different chemokines compared between 5828 HCC patients and 4909 controls; and 12 different chemokines receptors compared between 2053 patients and 2285 controls. The results of meta-analysis indicated that concentrations of CCL20, CXCL8 and CXCR4 in the HCC patients were significantly higher than those in the controls (SMD of 6.18, 1.81 and 1.04, respectively). Therefore, higher concentration levels of CCL20, CXCL8 and CXCR4 may indicate the occurrence of HCC Future research should explore the putative mechanisms underlying this linkage. Meanwhile, attempts can be made to replicate the existing findings in prospective cohort populations and explore the cause-and-effect relationships pertaining to this linkage in order to develop new diagnostic and therapeutic strategies for HCC.

Eomes promotes esophageal carcinoma progression by recruiting Treg cells through the CCL20-CCR6 pathway

Eomesodermin (Eomes) is a T-box transcription factor that drives the differentiation and function of cytotoxic lymphocytes. However, the underlying function and mechanism of Eomes in tumor cells remains elusive. Here, we studied the role of Eomes in human esophageal squamous cell carcinoma (ESCC). Using 2 human ESCC cell lines, we found that Eomes knockdown reduced esophageal cancer cell proliferation and that the esophageal cancer cell cycle was blocked in the G2/M phase. Mechanistically, we identified CCL20 as the main downstream target of Eomes. Furthermore, we found that CCL20 could chemoregulate regulatory T cells (Tregs) through their specific receptor CCR6, then promoting the proliferation of esophageal cancer cells. Eomes knockdown also delayed the growth of human ESCC xenografts in BALB/c nude mice. Importantly, in 133 human ESCC tissues, high Eomes levels were associated with poor clinical prognosis. Overall, our findings suggested that the Eomes-CCL20-CCR6 pathway plays a vital role in human ESCC progress. Therefore, targeting this pathway may represent a promising strategy for controlling human ESCC.

CRISPR Screening of CAR T Cells and Cancer Stem Cells Reveals Critical Dependencies for Cell-Based Therapies

Glioblastoma (GBM) contains self-renewing GBM stem cells (GSC) potentially amenable to immunologic targeting, but chimeric antigen receptor (CAR) T-cell therapy has demonstrated limited clinical responses in GBM. Here, we interrogated molecular determinants of CAR-mediated GBM killing through whole-genome CRISPR screens in both CAR T cells and patient-derived GSCs. Screening of CAR T cells identified dependencies for effector functions, including TLE4 and IKZF2. Targeted knockout of these genes enhanced CAR antitumor efficacy. Bulk and single-cell RNA sequencing of edited CAR T cells revealed transcriptional profiles of superior effector function and inhibited exhaustion responses. Reciprocal screening of GSCs identified genes essential for susceptibility to CAR-mediated killing, including RELA and NPLOC4, the knockout of which altered tumor-immune signaling and increased responsiveness of CAR therapy. Overall, CRISPR screening of CAR T cells and GSCs discovered avenues for enhancing CAR therapeutic efficacy against GBM, with the potential to be extended to other solid tumors. SIGNIFICANCE: Reciprocal CRISPR screening identified genes in both CAR T cells and tumor cells regulating the potency of CAR T-cell cytotoxicity, informing molecular targeting strategies to potentiate CAR T-cell antitumor efficacy and elucidate genetic modifications of tumor cells in combination with CAR T cells to advance immuno-oncotherapy.This article is highlighted in the In This Issue feature, p. 995.

Function of TREM1 and TREM2 in Liver-Related Diseases

TREM1 and TREM2 are members of the triggering receptors expressed on myeloid cells (TREM) family. Both TREM1 and TREM2 are immunoglobulin superfamily receptors. Their main function is to identify foreign antigens and toxic substances, thereby adjusting the inflammatory response. In the liver, TREM1 and TREM2 are expressed on non-parenchymal cells, such as liver sinusoidal endothelial cells, Kupffer cells, and hepatic stellate cells, and cells which infiltrate the liver in response to injury including monocyte-derived macrophages and neutrophils. The function of TREM1 and TREM2 in inflammatory response depends on Toll-like receptor 4. TREM1 mainly augments inflammation during acute inflammation, while TREM2 mainly inhibits chronic inflammation to protect the liver from pathological changes. Chronic inflammation often induces metabolic abnormalities, fibrosis, and tumorigenesis. The above physiological changes lead to liver-related diseases, such as liver injury, nonalcoholic steatohepatitis, hepatic fibrosis, and hepatocellular carcinoma. Here, we review the function of TREM1 and TREM2 in different liver diseases based on inflammation, providing a more comprehensive perspective for the treatment of liver-related diseases.

Chemokines and their Receptors: Multifaceted Roles in Cancer Progression and Potential Value as Cancer Prognostic Markers

Chemokines are chemotactic cytokines that mediate immune cell chemotaxis and lymphoid tissue development. Recent advances have indicated that chemokines and their cognate receptors play critical roles in cancer-related inflammation and cancer progression. On the basis of these findings, the chemokine system has become a new potential drug target for cancer immunotherapy. In this review, we summarize the essential roles of the complex network of chemokines and their receptors in cancer progression. Furthermore, we discuss the potential value of the chemokine system as a cancer prognostic marker. The chemokine system regulates the infiltration of immune cells into the tumor microenvironment, which induces both pro- and anti-immunity and promotes or suppresses tumor growth and proliferation, angiogenesis, and metastasis. Increasing evidence indicates the promising prognostic value of the chemokine system in cancer patients. While CCL2, CXCL10, and CX3CL1/CX3CR1 can serve as favorable or unfavorable prognostic factors depending on the cancer types, CCL14 and XCL1 possess good prognostic value. Other chemokines such as CXCL1, CXCL8, and CXCL12 are poor prognostic markers. Despite vast advances in our understanding of the complex nature of the chemokine system in tumor biology, knowledge about the multifaceted roles of the chemokine system in different types of cancers is still limited. Further studies are necessary to decipher distinct roles within the chemokine system in terms of cancer progression and to validate their potential value in cancer prognosis.

Guidance factors orchestrating regulatory T cell positioning in tissues during development, homeostasis, and response

Over their lifetime, regulatory T cells (Treg) recalibrate their expression of trafficking receptors multiple times as they progress through development, respond to immune challenges, or adapt to the requirements of functioning in various non-lymphoid tissue environments. These trafficking receptors, which include chemokine receptors and other G-protein coupled receptors, integrins, as well as selectins and their ligands, enable Treg not only to enter appropriate tissues from the bloodstream via post-capillary venules, but also to navigate these tissues to locally execute their immune-regulatory functions, and finally to seek out the right antigen-presenting cells and interact with these, in part in order to receive the signals that sustain their survival, proliferation, and functional activity, in part in order to execute their immuno-regulatory function by altering antigen presenting cell function. Here, we will review our current knowledge of when and in what ways Treg alter their trafficking properties. We will focus on the chemokine system and try to identify specialized, non-redundant roles of individual receptors as well as similarities and differences to the conventional T cell compartment.

Cancer Immunotherapies Targeting Tumor-Associated Regulatory T Cells

Tumor-associated regulatory T cells (Tregs) are important effectors in the tumor microenvironment (TME), acting as accomplices in the promotion of tumor progression. Currently, the importance of removing the immunosuppressive activity in the TME has received its due attention, and Tregs have been focused on. The cytokine-receptor axes are among the essential signaling pathways in immunocytes, and tumor-associated Tregs are no exception. Therefore, manipulating cytokine-receptor pathways may be a promising effective strategy for treating various malignancies. Here, we summarize the classification, immunosuppressive mechanisms, existing immunotherapies, and potential biomarkers related to tumor-infiltrating Tregs to guide the development of effective cancer immunotherapies.

Chemokine ligand 20 (CCL20) expression increases with NAFLD stage and hepatic stellate cell activation and is regulated by miR-590-5p

CCL20 (CC chemokine ligand 20) is emerging as an important regulatory molecule in a pathway common to virus infection, alcoholic hepatitis, and non-alcoholic fatty liver disease (NAFLD) leading to the development of hepatic fibrosis. We previously observed upregulation of CCL20 in patients with NAFLD fibrosis and human hepatic stellate cells (LX-2 cells) in response to lipid loading. To date, the mechanisms mediating the relationship between CCL20 and hepatic fibrogenesis remain unknown. In this study, we sought to characterize the molecular mechanisms by which CCL20 may contribute to fibrogenesis in NAFLD. We observed that CCL20 levels increased with worsening severity of liver histology in NAFLD patients (normal < steatosis < inflammation < fibrosis) and during LX-2 cell activation in a time-dependent manner. We found that treatment of LX-2 cells with CCL20 corresponded with increased levels of CCL20 and ACTA2, and decreased levels of PLAU and SERPINE1, effects mitigated by CCL20 knockdown. We identified a putative binding site for miR-590-5p, which we previously reported to be downregulated in NAFLD fibrosis, in the CCL20 3' untranslated region (3'UTR), and found that exogenous miR-590-5p functionally interacted with the CCL20 3'UTR to downregulate its expression. Transfection of LX-2 hepatic stellate cells with miR-590-5p mimic or silencing RNA resulted in decreased or increased CCL20 levels, respectively. Our results indicate an association between CCL20 and hepatic stellate cell activation that includes modulation of key ECM components and functional interactions with a miRNA previously implicated in NAFLD fibrosis. Together, these findings support a novel mechanism by which CCL20 may promote fibrogenesis in NAFLD.

The Diagnostic Value of Chemokine/Chemokine Receptor Pairs in Hepatocellular Carcinoma and Colorectal Liver Metastasis

Chemokines and their receptors have been proposed to play important roles in tumor progression and metastasis. To investigate their roles in the progression of primary and metastatic malignant liver tumors and their prognosis, we compared expression profiles of CXCL12/CXCR4, CCL20/CCR6, and CCL21/CCR7 in hepatocellular carcinoma (HCC) and colorectal liver metastases (CRLM). Immunohistochemistry was used to analyze the expression levels of the chemokine/chemokine receptor pairs in 29 HCC and 11 CRLM specimens and adjacent non-cancerous tissues, and correlations with clinicopathological variables and overall survival were determined. CCL20/CCR6 expression was higher in HCC than in adjacent non-cancerous tissues. High CCR6 expression in HCC was negatively associated with 5-year survival rate and was an independent prognostic factor for overall survival of HCC patients, whereas differences were not observed between CRLM and adjacent tissues. Furthermore, significantly higher expression of CCL21/CCR7 was found in CRLM than in HCC. In summary, the CCL20/CCR6 axis was elevated in HCC but not in CRLM, whereas the CCL21/CCR7 axis was elevated in CRLM but not in HCC.

Dual effect of T helper cell 17 (Th17) and regulatory T cell (Treg) in liver pathological process: From occurrence to end stage of disease

Liver disease is a complicated pathological status with acute or chronic progressions, causing a series of damages to liver and massive burden to public health and society. Th17 and Treg, two subsets of CD4⁺ T helper cells, seem to keep a subtle balance in the maintenance of organic immune homeostasis including liver. The dysfunction of Th17/Treg balance in liver has been proved associated with hepatic injury and disease. Herein, we summarized the research advance of Th17 and Treg cells in different phenotypes of liver diseases in the past decade. It is known to all that hepatic diseases start from stimulations or infections like virus, autoimmune, alcohol and so on in the early stage, which would cause inflammation. With the disease consistently existed, severe outcomes like cirrhosis and hepatocellular carcinoma appear finally. In conclusion, it is found that Th17 and Treg cells serve as an important role in the immune response imbalance of liver diseases from the beginning to the end stage. However, the effect of these two subsets of CD4⁺ T helper cells is not a stereotype. Pathological role which exacerbates the disease and protective character which inhibits damage to liver are co-existed in the effect of Th17 and Treg cells. Still, more studies should be carried out to enrich the understandings of liver disease and Th17/Treg immune balance in the future.

Sphingosine 1 phosphate receptor-1 (S1P1) promotes tumor-associated regulatory T cell expansion: leading to poor survival in bladder cancer

Regulatory T cells (Tregs) represent an important contributor to cancer immune escape, but the molecular mechanism responsible for Treg expansion in tumors is heterogeneous and unclear. Here, we investigated the role of S1P1, a receptor of the bioactive lipid sphingosine 1-phosphate (S1P), in regulating the crosstalk between tumor cells and tumor-associated Tregs in bladder cancer (BC). We found that the frequency of CD4⁺Foxp3⁺ Tregs was increased in circulating and tumor-infiltrating lymphocytes from BC patients. S1P1 expression was upregulated in BC tissues compared with tumor-adjacent tissues and was positively correlated with the density of tumor-infiltrated Foxp3⁺ Tregs. Both S1P1 and Treg predicted poor overall survival in BC patients. The in vitro data paralleled the in vivo data and suggested that the activation or overexpression of S1P1 in BC cells promoted the generation of BC-induced (i)Tregs from CD4⁺CD25⁻cells, and the generation of these cells was reversed by treatment with anti-IL-10 or anti-TGF-β. Moreover, S1P1 promoted Treg migration mediated by BC cells. Mechanistically, S1P1 activated the TGF-β signaling pathway, leading to the secretion of TGF-β and IL-10 from BC cells. In total, our findings suggest that S1P1 induces tumor-derived Treg expansion in a cell-specific manner and serves as a potent prognostic biomarker and therapeutic target in BC.

Multipotent mesenchymal stromal cells play critical roles in hepatocellular carcinoma initiation, progression and therapy

Hepatocellular carcinoma (HCC) is the most common type of primary liver cancer, with high morbidity, relapse and mortality rates. Multipotent mesenchymal stromal cells (MSCs) can be recruited to and become integral components of the HCC microenvironment and can influence tumor progression. This review discusses MSC migration to liver fibrosis and the HCC microenvironment, MSC involvement in HCC initiation and progression and the widespread application of MSCs in HCC-targeted therapy, thus clarifying the critical roles of MSCs in HCC.

Rediscovery of NF-κB signaling in nasopharyngeal carcinoma: How genetic defects of NF-κB pathway interplay with EBV in driving oncogenesis?

Nasopharyngeal carcinoma (NPC) is a unique EBV-associated subtype of head and neck cancer, which has the highest incidence in Southern China and eastern South Asia. The interaction between genetic risk factors and environmental challenge, have been considered to contribute to the development of nasopharyngeal carcinogenesis. Constitutive activation of NF-κB signaling has been seen in NPC tissues and is associated with unfavorable prognosis. Recently, several whole exome sequencing study consistently revealed that high frequency mutations of NF-κB pathway negative regulators is common in nasopharyngeal carcinoma, which reinforce the importance of NF-κB driving oncogenesis. This review focuses on the current state of research in role of NF-κB in NPC carcinogenesis. We summarized the newly identified loss of function (LOF) mutations on NF-κB negative regulators leading to it's activation bypass LMP-1 stimulation. We discussed the critical role of NF-κB activation in immortalization and transformation of nasopharygeal epithelium. We also depicted how NF-κB signaling mediated chronic inflammation contribute to persistent EBV infection, immune evasion of EBV infected cells, metabolic reprogramming, and cancer stem cells (CSCs) formation in NPC. Lastly, we discussed the clinical resonance of targeting NF-κB for NPC precise therapy.

Impaired T cell function in malignant pleural effusion is caused by TGF-β derived predominantly from macrophages

Malignant pleural effusion (MPE) is an indication of advanced cancer. Immune dysfunction often occurs in MPE. We aimed to identify the reason for impaired T cell activity in MPE from lung cancer patients and to provide clues toward potential immune therapies for MPE. The surface inhibitory molecules and cytotoxic activity of T cells in MPE and peripheral blood (PB) were analyzed using flow cytometry. Levels of inflammatory cytokines in MPE and PB were tested using ELISA. TGF-β expression in tumor-associated macrophages (TAMs) was also analyzed. The effect of TAMs on T cells was verified in vitro. Lastly, changes in T cells were evaluated following treatment with anti-TGF-β antibody. We found that expression levels of Tim-3, PD-1 and CTLA-4 in T cells from MPE were upregulated compared with those from PB, but levels of IFN-γ and Granzyme B were downregulated (p < 0.05). The amount of TGF-β was significantly higher in MPE than in PB (p < 0.05). TGF-β was mainly produced by TAMs in MPE. When T cells were co-cultured with TAMs, expression levels of Tim-3, PD-1 and CTLA-4 were significantly higher than controls, whereas levels of IFN-γ and Granzyme B were significantly decreased, in a dose-dependent manner (p < 0.05). In vitro treatment with anti-TGF-β antibody restored the impaired T cell cytotoxic activity in MPE. Our results indicate that macrophage-derived TGF-β plays an important role in impaired T cell cytotoxicity. It will therefore be valuable to develop therapeutic strategies against TGF-β pathway for MPE therapy of lung cancer.

Regulatory T cells function at the early stage of tumor progression in a mouse model of tongue squamous cell carcinoma

The objective of this study was to observe the distribution of regulatory T cells (Tregs) in the development of tongue squamous cell carcinoma (SCC) and to determine the role of Tregs in the progression of tongue SCC. A mouse model of 4-nitroquinoline-1-oxide (4NQO)-induced-tongue SCC was established. The expression of Forkhead box P3 (Foxp3), interleukin 10, transforming growth factor-β, chemokine CC motif ligands 17, 20, and CC chemokine receptor 4 was determined using real-time quantitative polymerase chain reaction. Foxp3 expression was also analyzed using immunohistochemistry. The results were compared with those of control mice and of 4NQO-treated mice treated with a cyclooxygenase-2 (COX-2) inhibitor. Well to moderately differentiated tongue SCC was induced in all of the experimental mice. The amount of Tregs of the experimental mice was over 10 times as much as control mice at the early stage of tumor progression. COX-2 inhibitor did not prevent the progression of tongue SCC and did not reduce the total amount of Tregs. Tregs function at the early stage of the development of tongue SCC, and it may be effective to suppress Tregs at the early stage of tumor progression for the treatment and/or prevention of tongue SCC.